Tar kettles in the prior art have been provided with doors in the top thereof, which doors are opened to permit recharging of the kettle by workmen dropping in chunks of asphalt which have been broken by an axe from wrapped cylinders of asphalt. Even reasonably careful dropping of these chunks into the hot tar in the kettle causes splashing and the free access of air results in the tar frequently catching on fire. Such kettles have no provision against emanation of fumes and are dangerous to operate. Proposals have been made to re-locate the doors on tar kettles and very satisfactory temperature sensing apparatus have been incorporated in kettles to minimize overheating and the danger of fire. The present invention is incorporated with a tar kettle which may be already equipped with such temperature sensing and control apparatus. There is a need, however for improvements making such a tar kettle safer and more easily operated as well as non-polluting.